JP2001038638A - Resinoid bonded grinding wheel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the friction heat during the grinding, to improve the strength and hardness of a abrasive grain layer, and to prevent the loss in shape. SOLUTION: In this grinding wheel, superfine abrasive grains 13 are diffused in a binder phase 12 of a phenol resin. Fillers 14 containing both solid lubricants of CaF2 15 and ZnO 16 by 3-50 vol.% of the resin binder phase are diffused. ZnO 16 is contained by 10-40 vol.% of the total amount of the tillers while 15 vol.% of CaF2. When ZnO is contained less than 10 vol.%, the strength and hardness of the abrasive grain layer are small, the shape is lost, and the suppressive effect cannot be obtained. When ZnO is contained more than 40 vol.%, the strength and hardness are too large, the grinding resistance is increased, and the friction heat in the abrasive grain layer is increased. ZnO 16 is diffused in the resin binder phase 12 in a condition of the secondary particles in which multi-crystal primary particles are aggregated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin-bonded grindstone used for, for example, mirror grinding.

[0002]

2. Description of the Related Art Resin bond grindstones are prepared by mixing a raw material powder of a thermosetting resin such as an epoxy resin or a phenol resin with superabrasive grains such as diamond or CBN, and forming the mixture alone or, if necessary, with a base metal. After pressing, press molding and baking to form a resin bond abrasive grain layer. Resin bond whetstones have a relatively soft and brittle resin binder phase that holds superabrasive grains, so when grinding relatively hard work materials, the tips of the superabrasive grains wear and reduce sharpness. Faster, the superabrasive grains fall off as the resin binder phase supporting the superabrasive grains is crushed or worn. As a result, resin-bonded grinding wheels have the disadvantage of severe wear.However, the sharpness is less likely to occur due to clogging of the ground surface and abrasion of the abrasive grains. Since the retained superabrasive grains have an elastic effect, the work material is less damaged and the finished surface is good. Therefore, it has an advantage that it can be suitably used for grinding requiring small surface roughness, such as mirror grinding of a work material such as a semiconductor wafer.

[0003] By the way, in the conventional resin bond whetstone,
There is a type in which a solid lubricant such as hBN or graphite is dispersed as a filler in a resin binder phase in order to suppress frictional heat generated by grinding resistance. For example, in the resin bond grinding wheel 1 shown in FIG. 6, diamond super abrasive grains 4 are dispersed and arranged in a resin binder phase 3 made of a phenol resin as an abrasive layer 2, and CaF ₂ (calcium fluoride) 5 is used as a solid lubricant. Are added and dispersed. When grinding is performed using such a resin-bonded grindstone 1, when CaF ₂ 5 in the resin-bonded phase 3 is sequentially dropped together with the resin-bonded phase 3 and the superabrasive grains 4, the superabrasive grains 4 function as a lubricant. Grinding can be performed smoothly, and frictional heat of the abrasive layer 2 and the work material can be suppressed.

[0004]

However, in the above-described resin-bonded grindstone 1, cutting resistance can be reduced by using a solid lubricant as a filler, but at the same time, the strength of the resin bonding phase 3 is reduced by the amount of the solid lubricant. Because of the reduction, the shape of the abrasive layer 2 is more quickly deformed, and the life of the grinding wheel is shortened. In view of such problems, an object of the present invention is to provide a resin-bonded grindstone capable of improving mechanical strength, suppressing shape collapse, and improving life.

[0005]

A resin bond grindstone according to the present invention is a resin bond grindstone in which superabrasive grains are dispersed and arranged in a resin binder phase, wherein ZnO is dispersed and arranged as a filler in the resin binder phase. It is characterized by becoming. By dispersing ZnO in the resin binder phase, the strength and hardness of the abrasive layer can be improved and the shape collapse of the abrasive layer can be suppressed,
The whetstone life can be improved.

Further, ZnO may be dispersed in the resin binder phase in the form of secondary particles in which primary particles made of polycrystals are aggregated. When the resin binder phase is crushed or worn by grinding and the superabrasives fall off, the secondary particles of ZnO exposed on the surface of the abrasive layer are formed by agglomeration of primary particles composed of polycrystals. Although the interface strength is low, it is easy to separate and fall off as primary particles, but during grinding, it dissolves in the grinding fluid and the primary particles are separated at any time and partly elutes as zinc hydroxide. Since it is smaller than the grain, it does not adversely affect the grinding performance. In addition, the remaining concave portions are formed as chip pockets by dropping ZnO from the surface of the abrasive grain layer, and the chips can be stored and smoothly discharged, so that clogging is less likely to occur. In addition, Z of secondary particle form
nO preferably has a smaller particle size than the superabrasive particles.
When the secondary particles have a size equal to or greater than the particle size of the superabrasive,
This is because the removal of ZnO sharply lowers the strength of the resin binder phase and promotes the removal of the superabrasive grains, and the wear of the grindstone proceeds.

Further, a solid lubricant may be dispersed in the resin binder phase. Since the abrasive layer contains a solid lubricant as another filler, it is necessary to smoothly grind the workpiece with superabrasive grains during grinding and to suppress the frictional heat of the abrasive layer and the workpiece. Can be. CaF ₂ , h as solid lubricant
BN, graphite (graphite) or the like can be used.
The filler containing ZnO and the solid lubricant may be contained in the resin binder phase in a range of 3 to 50 vol%. 3v
If it is less than ol%, it is not possible to suppress frictional heat during grinding and improve the strength and hardness of the abrasive layer, and if it exceeds 50 vol%, the content of the resin binder phase is relatively reduced and the super abrasive is retained. A problem occurs in which the force is reduced.

[0008] ZnO is 10 to 4 in the total amount of the filler.
0 vol% may be contained. If ZnO is less than 10 vol%, the strength and hardness of the abrasive layer are small and the effect of suppressing shape collapse cannot be obtained. If it exceeds 40 vol%, the hardness increases but the strength decreases and the life of the grindstone is shortened. Further, at least one of potassium sulfate, sodium nitrate and potassium nitrate may be contained in the resin binding phase. By containing any of these, when they dissolve in the grinding fluid during grinding, an endothermic reaction occurs, which can suppress an increase in the temperature of the grinding surface of the grinding wheel, and has an effect of extending the life of the grinding wheel.

[0009]

Embodiments of the present invention will be described below.
This will be described with reference to the drawings. FIG. 1 is a resin board according to an embodiment.
FIG. 2 is an enlarged cross-sectional view of the abrasive layer of the grinding wheel shown in FIG.
Partial vertical cross-sectional view and figure of a cup-type grinding wheel with layers attached to the base metal
3 shows the powder structure of ZnO contained in the abrasive layer.
(A) is a diagram showing the crystal structure of the primary particles, (b) is a diagram showing the secondary
FIG. 3 is a diagram showing a structure of a particle. Resin bond abrasive shown in Figure 1
The stone 9 is, for example, a grindstone for mirror surface grinding.
For example, as shown in FIG.
Stone base) may be fixed to the substantially circular tip portion,
A grindstone can be constructed only by the abrasive layer 10 without providing a base metal.
May be implemented. The abrasive layer 10 is made of, for example,
Resin bonding with thermosetting resin such as knol resin as main plastic
Phase 12 and a diamond dispersed in the resin-bound phase 12
(Or CBN or the like).
Further, plural kinds of fillers 14 are separated in the resin binder phase 12.
Are dispersed and the first filler is used as a solid lubricant
CaF _Two(Calcium fluoride) 15 and a second filter
The color is ZnO (zinc oxide) 16 in powder form.
Here, CaF is used as a solid lubricant._Two15 etc. as the resin binding phase
12 to reduce frictional heat due to grinding resistance.
And by containing ZnO16
By improving the strength and hardness of the abrasive layer 10 and suppressing shape collapse
Wear.

The resin bond grinding wheel 9 for mirror grinding is
In order to finish the surface roughness of the work material small for that application, the components such as superabrasive grains 13, CaF ₂ 15, ZnO 16, etc. are smaller in diameter than the same type of resin-bonded grinding wheel for other applications, and are uniform and homogeneous. Have been. In particular, as shown in FIG. 2, when the surface is ground with the abrasive layer 10 using the cup-type grindstone 8, a large number of superabrasive particles 13 are simultaneously formed on the work material because large-area contact grinding is performed. The load is small and the load is small due to the small grinding pressure applied to the individual superabrasive grains 13 due to the contact with the surface. Therefore, the holding force of the superabrasive grains 13 is high, and the load applied during grinding is
It is necessary to directly contribute to the grinding process without escaping through the hole. For that purpose, ZnO16 is added to increase the strength and hardness of the resin binder phase 12, and at the same time, to suppress the friction due to the contact resistance between the abrasive layer 10 and the work material during the grinding process, the welding of the resin to the processing surface, and the like. It is necessary to add a lubrication effect to

Therefore, the particle size of superabrasive particles 13 is # 1200 to
It is preferable to use # 5000 mesh. The reason is that if the particle size is larger than # 1200 mesh, the surface roughness of the ground surface is reduced and mirror polishing cannot be performed. If the particle size is smaller than # 5000 mesh, the grinding efficiency is significantly reduced. The shape of the superabrasive grains 13 is preferably a blocky or a polyhedral shape close thereto, but irregular abrasive grains may be used as long as they are not extremely scaly. Super abrasive 1 in abrasive layer 10
The content of 3 is set to 15 to 40% by volume, and the remainder becomes the resin binding phase 12. The reason is that if it is less than 15 vol%, the content of abrasive grains decreases and sufficient grinding performance cannot be obtained.
%, The clogging is likely to occur, so that the grinding performance also deteriorates.

The filler 1 contained in the resin binder phase 12
The total amount of 4 is 3 to 50 vol% in volume ratio. If the content is less than 3 vol%, the effect of a lubricant or the like due to the inclusion of a filler, for example, the effect of reducing frictional heat due to grinding resistance does not occur, and the effect of preventing shape collapse due to improvement in strength and hardness does not occur. On the other hand, if the content exceeds 50 vol%, the resin content relatively decreases, so that the holding strength of the superabrasive grains 13 is reduced and the abrasion of the abrasive grain layer 10 becomes severe. In addition, the total amount of the filler 14 in the abrasive grain layer 11 is preferably set to 10 to 50 vol%, particularly 30 to 45 vol% in volume ratio. Filler 14
Thus, the suppression of frictional heat due to the cutting resistance of the resin bond grindstone 9 and the suppression of shape collapse due to the improvement in strength and hardness can be achieved reliably, and if it is 30 vol% or more, these effects can be achieved more reliably. On the other hand, if the content exceeds 50 vol%, the content of the resin relatively decreases.
3, the holding strength of superabrasive grains 13 can be reliably improved if the holding strength of super abrasive grains 13 is reduced to 45 vol% or less. The content of ZnO 16 in the filler 14 is 10 to 40 vo in volume ratio.
l%. If it is less than 10 vol%, the strength and hardness of the abrasive layer 10 cannot be improved, and if it exceeds 40 vol%, the content of CaF ₂ , which is a solid lubricant, relatively decreases, and the frictional heat suppressing effect decreases. . In short, the content of ZnO16 it is required less content than CaF ₂ as a first filler.

Next, the form of ZnO 16 as the second filler in the resin binder phase 12 will be described. ZnO
Numeral 16 denotes a particulate powder. As shown in FIG. 3A, the primary particles 16A are made of a polycrystalline body in which ZnO single crystals 16a are gathered, and as shown in FIG. The primary particles 16 </ b> A are dispersed in the resin binder phase 12 as powder in the form of secondary particles in which the primary particles 16 </ b> A are aggregated. Desirably, the secondary particle ZnO 16 is smaller than the particle diameter of the superabrasive grains 13 because the matrix strength of the resin bonding phase 12 in the vicinity of the superabrasive grains 13 when the ZnO 16 is larger than the particle diameter of the superabrasive grains 13. Is sharply reduced, and the superabrasive grains 13 easily fall off, thereby promoting wear. Therefore, the primary particles 16A have a smaller particle size. Further, by dispersing and dispersing in the resin binder phase 12, the strength and hardness of the resin binder phase 12 are improved. The primary particles 16A are hardly broken because they are polycrystalline in the state of the primary particles 16A, but the secondary particles have a low bonding strength at the interface between the bonded primary particles 16A, and easily separate and fall off to form the primary particles 16A. Easy to return to. Moreover, since ZnO 16 is dissolved in water, the secondary particles of ZnO 16 exposed on the surface of the abrasive grain layer 10 by the self-sharpening action during the grinding of the resin bond grindstone 9 are ground so that the primary particles 16A are ground as shown in the following equation. It dissolves in water in the liquid and elutes as zinc hydroxide. ZnO + H ₂ O → Zn (OH) ₂

Since the resin-bonded grindstone 9 according to the present embodiment is constructed as described above, the resin-bonded grindstone 9 is used as, for example, the cup-shaped grindstone 8 shown in FIG. 2 to cut a work material such as a semiconductor wafer. In the case of mirror polishing, the abrasive layer 12 comes into surface contact with the workpiece as shown in FIG. In FIG. 4, a substantially arc-shaped hatched portion is a grinding surface 12 </ b> A formed by the abrasive layer 12. At that time, since the powdery ZnO 16 as the second filler is dispersed in the resin binder phase 12, the strength and hardness of the abrasive grain layer 12 are improved.
The grinding pressure directly contributes to the grinding through the superabrasive grains 13 without reducing the grinding pressure by deforming the resin bonding phase 12 as the bond matrix. Therefore, mirror polishing with small surface roughness can be efficiently performed with a relatively small grinding pressure.
At the same time, since ZnO 16 is dispersed in the abrasive layer 10, the strength and hardness of the abrasive layer 10 are high, and mirror polishing with a small surface roughness can be performed in this point, and moreover, compared with the conventional grinding stone, The falling of the abrasive grains 13 is slow, and the life of the resin bond grinding stone 9 is prolonged.

Then, as the grinding proceeds, the resin binder phase 12 is gradually crushed or worn and collapsed, and the superabrasive grains 13 fall off and spontaneously generate a cutting edge. The solid lubricant CaF ₂ suppresses an increase in frictional heat due to rubbing friction between the work material and the surface of the abrasive grain layer 10 and improves the sharpness of the superabrasive grains 13. At the same time, ZnO 16 in the abrasive grain layer 10 is also exposed on the surface of the abrasive grain layer 10 to be ground. At this time, ZnO 16 is converted from the primary particles forming the secondary particles to the primary particles as shown in the following equation. The particle interface dissolves in the grinding fluid. ZnO + H ₂ O → Zn (OH) ₂ Therefore, the primary particles 16A are gradually separated from the secondary particles and fall off. Since the dropped primary particles 16A are smaller than the superabrasive grains 13, the dropped ZnO 16 does not adversely affect the grinding process, the abrasive layer 12, and the work material.

For this reason, secondary particles of ZnO16
After the particles fall off as primary particles, concave portions remain on the surface of the abrasive layer 10 as shown in FIG.
7 will function. Therefore, the chips generated during grinding are stored in the tip pocket 17 and gradually discharged, so that the chips do not stay around the superabrasive grains 13 and are smoothly discharged without clogging.

Incidentally, a solid lubricant is used as the first filler, for example, CaF ₂ (calcium fluoride) 15
Was used, but instead of hBN,
Graphite (graphite) or the like may be used. Abrasive layer 1
Filler 1 to promote the cooling action of the grinding action surface
As part of 4, at least one of potassium sulfate, sodium nitrate and potassium nitrate may be used.

As described above, according to the present embodiment, the solid lubricant CaF ₂ 15 as the first filler is dispersed in the binder resin phase 12 of the abrasive layer 10 of the resin bond grinding wheel 9. In addition to being able to improve the sharpness of superabrasive grains by suppressing frictional resistance during grinding, Zn as a second filler
By dispersing O16, the strength and hardness of the resin binder phase 12 can be improved and the shape collapse of the abrasive grain layer 10 can be suppressed, and a small grinding pressure is required especially when mirror-grinding is performed in surface contact with the work material. Efficient and highly accurate grinding can be performed by efficiently applying the superabrasive 13 to the cutting blade. Moreover, when grinding, ZnO16
Since the primary particles 16A dissolve in the grinding fluid and easily separate and fall off from the state of the secondary particles, the primary particles 16A do not adversely affect the abrasive layer 12 and the work material. The concave portion of ZnO16 of the particle is the tip pocket 17
As a result, the chips are stored and discharged, so that smoother grinding can be performed without causing clogging.

Next, the resin bond grinding wheel 9 according to the embodiment will be described.
The grinding test performed for will be described. First, FIG.
In the resin-bonded grindstone 9 of the cup-shaped grindstone 8 shown in FIG. 1, a phenol resin was used as the resin binder phase 12 of the abrasive grain layer 10 to make the total 70 vol%, and diamond abrasive grains as the superabrasive grains 13 were dispersed at 30 vol%. And resin binding phase 1
For the composition of No. ₂ , the phenol resin was 65 vol%, the filler 14 was 35 vol%, and the filler 14 used was CaF ₂ as the first filler and ZnO as the second filler. Table 1 below shows the ratio of ZnO in the filler.
As shown in Examples 1 and 2, 5 vol% (the ratio in the total amount of the filler: 14.3 vol%) and 10 vol% (the ratio in the total amount of the filler: 14.3 vol%) were used as 10 and 40 vol%.
Comparative Examples 1, 2, 3, and 4 were those in which the value was out of the range, and Conventional Example 1 in which ZnO was not added.

[0020]

[Table 1] Composition of resin-bonded phase of resin-bonded grindstone (vol%) CaF ₂ ZnO (proportion of total filler) K ₂ SO ₄ phenolic resin (vol%) (vol%) (vol%) (vol%) Example 1 30 5 (14.3%) 65 Example 2 25 10 (28.6%) 65 Example 3 15 10 (28.6%) 10 65 Comparative Example 1 34 1 (2.9%) 65 Comparative Example 232 3 (8.6%) 65 Comparative Example 3 20 15 (42.9%) 65 Comparative Example 4 15 20 (57.1%) 65 Conventional Example 1 35 0 65

Next, a grinding test was performed on each of the resin-bonded grindstones having the resin bonding phases shown in Table 1 as cup-shaped grindstones 8 shown in FIG. Examples 1, 2 and Comparative Examples 1, 2, 3,
4. With respect to Conventional Example 1, the bending strength (kg / mm ² ), surface hardness (HRf), spindle current value (A) of the spindle motor, and grinding ratio of the resin bond grindstone 9 were measured. Here, the current value of the spindle motor is a current value required to rotate the spindle motor at a predetermined speed when the silicon wafer of the workpiece is ground while rotating the cup-type grindstone 8 at a constant speed of 3000 rpm ( A), and the current value supplied to the spindle motor was measured and used as the grinding resistance. The cup-type grindstone 8 is driven at a rotation speed of 3000 rpm, and 200 6-inch silicon wafers each having a thickness of 20
After grinding over μm, the bending strength (kg / mm ² ), surface hardness (HRf), spindle current value (A), and grinding ratio of the abrasive layer 12 were measured. Table 2 shows the measurement results.

[0022]

[Table 2] Measurement results of grinding characteristics of resin bond grindstone Bending strength Surface hardness Main shaft current value Grinding ratio (kg / mm ² ) (HRf) (A) Example 1 13.0 104 4.8 300 Example 2 14.5 105 4.5 380 Example 3 14.7 106 4.6 420 Comparative Example 1 12.0 102 5.4 250 Comparative Example 2 12.2 103 5.0 280 Comparative Example 3 14.8 106 5. 4 385 Comparative Example 4 15.0 106 9.6 Unmeasurable Conventional Example 1 12.0 102 5.5 245 In the grinding ratio, “measurable” means that the work material could not be measured due to burning. Say.

From the test results shown in Table 1 above, in Examples 1 and 2, the collapse in shape could be suppressed by the bending strength and surface hardness, the main shaft current value was 4.8 A or less, the grinding resistance was small, and the grinding ratio was low. It was 300 or more, which was good. In Example 3 containing potassium sulfate, an improvement in the grinding ratio was observed due to the cooling effect. On the other hand, in Comparative Examples 1 to 4 and Conventional Example 1, the spindle current value was 5.0 A or more, and the grinding resistance was high. In particular, in Comparative Examples 1 and 2, the second filler Z
Since the content of nO was less than 10 vol%, the bending strength and surface hardness were small, and the shape easily collapsed. Therefore, the grinding ratio was small and the wear resistance and the life were short. In Comparative Examples 3 and 4, since the ZnO content exceeded 40 vol%, the transverse rupture strength and surface hardness were too large, the main shaft current value was high, and the grinding resistance was large. In addition, although the grinding ratio was high, particularly in Comparative Example 4, the spindle current value reached 9.6 A, seizure occurred, and the grinding ratio could not be measured. In Conventional Example 1, the transverse rupture strength and surface hardness are small and the shape is likely to collapse. In addition, the spindle current value is high, the grinding resistance is large, the grinding ratio is extremely small, and the life is short. Therefore, considering the balance between bending strength and hardness, grinding resistance and grinding ratio, the amount of ZnO added to the filler 14 is 1
It is preferably in the range of 0 to 40 vol%. In this test, the filler 14 was measured at 35 vol% of the resin binder phase 12, but is applicable in the range of 3 to 50 vol%.

In the above description, an example in which the resin bond grindstone according to the present invention is used for mirror surface grinding has been described.
The resin-bonded grindstone according to the present invention may, of course, be employed for other types of grinding without being limited to this.

[0025]

As described above, the resin-bonded grindstone according to the present invention is formed by dispersing ZnO as a filler in the resin binder phase, so that the strength and hardness of the abrasive layer can be improved and the abrasive grain can be improved. The shape collapse of the layer can be suppressed, and the life of the grinding wheel can be improved.

Further, since ZnO is dispersed in the resin binder phase in the form of secondary particles in which primary particles composed of polycrystals are aggregated, the resin binder phase is crushed or worn by grinding, and the superabrasive grains fall off. In this case, the secondary particles of ZnO exposed on the surface of the abrasive layer are easily separated and dropped as primary particles, and the dropped primary particles have a smaller particle size than super-abrasive particles, so that they do not adversely affect the grinding performance. Absent. Also, from the surface of the abrasive layer, Z
When the nO falls off, a chip pocket is formed in the subsequent concave portion, and the chip can be stored and smoothly discharged, so that clogging is less likely to occur.

Further, since the solid lubricant is dispersed in the resin binder phase, it is possible to smoothly grind the work material with superabrasive grains during grinding and to suppress frictional heat of the abrasive layer and the work material. it can. In addition, since the filler containing ZnO and the solid lubricant is contained in the resin binder phase in the range of 3 to 50 vol%, the frictional heat is suppressed during grinding and the strength and hardness of the abrasive layer are improved at 3 vol% or more. In addition to achieving 50 vol% or less, the holding power of the superabrasive grains by the resin binder phase is high.

The ZnO content is 10 to 4 in the total amount of the filler.
Since 0 vol% is contained, the strength and hardness of the abrasive layer are improved and the shape collapse can be suppressed, and at the same time, the strength and hardness become too large, the grinding resistance increases, and the frictional heat of the abrasive layer decreases. It does not increase. Also, potassium sulfate,
Since at least one of sodium nitrate and potassium nitrate is contained, the temperature rise of the ground surface during grinding can be suppressed by the endothermic effect at the time of dissolving them by using these as a filler.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a resin-bonded grindstone according to an embodiment of the present invention.

FIG. 2 is a partial cross-sectional view of a cup-type grindstone in which the resin-bonded grindstone shown in FIG. 1 is mounted on a base.

FIG. 3 shows Zn contained in the abrasive layer shown in FIGS. 1 and 2.
FIG. 3 shows powder particles of O, (a) showing a polycrystalline primary particle, and (b) showing a secondary particle.

4 is a diagram showing a state where the surface of the work material is ground by the cup-type grindstone shown in FIG. 2 by hatching.

FIG. 5 is a cross-sectional view showing a state in which ZnO has dropped from an abrasive layer of the resin-bonded grindstone shown in FIGS. 1 and 2;

FIG. 6 is a cross-sectional view of a conventional resin-bonded grindstone.

[Explanation of symbols]

Reference Signs List 8 cup-type grindstone 9 resin-bonded grindstone 10 abrasive layer 12 resin binder phase 13 superabrasive 14 filler 15 CaF ₂ (first filler) 16 ZnO (second filler) 16A primary particles of ZnO

Claims (6)

[Claims] 1. A resin-bonded grinding wheel in which super-abrasive grains are dispersed in a resin-bound phase, wherein Z is contained in the resin-bound phase.
A resin-bonded grindstone characterized in that nO is dispersed and arranged as a filler. 2. The resin-bonded grinding wheel according to claim 1, wherein said ZnO is dispersed in a resin binder phase in the form of secondary particles in which primary particles made of polycrystals are aggregated. 3. The resin-bonded grindstone according to claim 1, wherein a solid lubricant is dispersed in the resin binder phase. 4. The resin-bonded grinding wheel according to claim 3, wherein the filler containing ZnO and the solid lubricant is contained in a range of 3 to 50 vol% in the resin binder phase. 5. The method according to claim 1, wherein the ZnO is 1% in the total amount of the filler.
2. The composition according to claim 1, wherein 0 to 40 vol% is contained.
5. The resin-bonded grindstone according to any one of items 4 to 4. 6. The resin-bonded grinding wheel according to claim 1, wherein the resin-bound phase contains at least one of potassium sulfate, sodium nitrate, and potassium nitrate.